1. Field of the Invention
The present invention relates to an information processing device for a diver, a control method, a control program, a recording medium thereof, diving equipment, and a method for controlling the diving equipment. In particular, the invention relates to an information processing device for a diver, a control method, a control program, a recording medium thereof, diving equipment, and a method for controlling the diving equipment that can be used in deep diving.
2. Background Information
It is conventionally known that nitrogen and other inhaled inert gases dissolved in the body as a result of diving form bubbles in the body and bring about decompression sickness. Also, in air diving, in which ordinary air is used as the breathing gas, the probability is high that so-called nitrogen poisoning will occur when the dive is made to a depth in excess of about 30 m, although the effect varies depending on the body mass or skill level.
Devices in which the information necessary to ensure diver safety, such as the current depth, the time needed to purge the excess inert gas accumulated in the body, or the safe ascent velocity, by means of a predetermined algorithm during diving, and the results are displayed on a liquid crystal display panel or other display are known as diver's information processing devices referred to as dive computers and designed to overcome the above-described drawbacks. Such a diver's information processing device is disclosed, for example, in Japanese Laid-Open Patent Publication No. 11-20787.
In addition, mixed gas diving, performed using a gas mixture of nitrogen and oxygen with an increased nitrogen concentration, is employed when a dive to a greater depth (deep diving) is involved.
With the aforementioned conventional mixed gas diving, however, the probability that nitrogen poisoning will occur is still high when the depth exceeds about 40 m. In addition, a switching error may lead to an oxygen deficiency in the case of a plurality of cylinders in which the diving gas is mixed in the same or different mixture ratios. Diving (deep diving) in which divers descend to depths in excess of 40 m are common in commercial diving or the like.
In view of the above, and based on the disclosure of the present invention, it is apparent to those skilled in the art that a need exists for an improved information processing device for a diver, control method, control program, recording medium thereof, diving equipment, and method for controlling the diving equipment. The present invention has been developed in response to such needs of the prior art and to other needs, which will become apparent to those skilled in the art from the disclosure given below.